Research

My general research interests center on the application of the comparative method as a tool for inferring and reconstructing soft tissues in extinct vertebrates, specifically dinosaurs. Cranial functional morphology, specifically, interests me because it offers the greatest insights into the sensory and motor capabilities of dinosaurs and how those capabilities served them in life. I am particularly interested in the paleoneurology (evolved form and inferred function) of dinosaur brains. The shape, size, and known components of the brains of living dinosaur relatives are informative for reconstructing dinosaur brains from fossil endocasts. Ultimately, brain reconstructions may provide further details about dinosaur sensory, motor, and integrative capabilities. My work requires techniques that are both classic and cutting-edge. I am trained in anatomical dissection as well as digital anatomical visualization and reconstruction. Additionally, I work hands-on with fossil specimens in our lab and in museum collections around the world to better understand the craniofacial anatomy of dinosaurs. 

 To be clear, I should mention that I work only with legally-obtained salvage specimens. I do not experiment on live animals.

 

Below are some examples of my work. 

Project |01 Dinosaur Brain Reconstruction

 

Study of the brain and its regions provides insight into how animals interact with their environment and each other. Unfortunately for me, dinosaur brains did not fossilize along with the rest of the skull. So, my research focuses on developing and applying the best possible approaches to modeling and studying dinosaur brains, as well as addressing questions of dinosaur brain evolution and ontogeny. I use evidence from fossilized brain cavities, digital brain endocasts, and modern animal brain anatomy to infer brain shape and size in dinosaurs. Dinosaur brain data are then used to probe hypotheses of evolution, ontogeny, and behavior. Previous and current studies include assessment of evolutionary rates for brain regions, a re-evaluation of Encephalization Quotients for dinosaurs, and further exploration of brain and brain region gross anatomy in the modern relatives of dinosaurs.

Project |02 DiceCT staining and scanning

 

My work relies heavily on 3D visualization and study of interactions between soft tissues (muscles, nerves, blood vessels, etc.) of the head with their associated hard tissues. As part of my effort to visualize these interactions, I refined diceCT protocols that use Lugol's iodine, a known contrast agent in radiology, to differentiate between life-like soft and hard tissues as well as among various soft tissue types on CT scans. The Visible Interactive Opossum project is just one example of the results of these protocols and is an outgrowth of the WitmerLab's Visible Interactive Animal Series. The diceCT protocols I developed for this have and continue to aid in my visualizations of intracranial tissues of extant archosaurs. Such visualizations inform inferences of dinosaur soft/hard tissue interactions and enhance my understanding of where and how the brain and its surrounding tissues interact with the bony brain cavity. Click the Witmerlab link above to access the contrast-enhanced CT data for the opossum for FREE!

Project |03 Digital Dissections 

 

One example of many...

As part of the collaborative Visible Interactive Ostrich project, I constructed a YouTube video to showcase ostrich cranial anatomy originally visualized by my colleagues in the WitmerLab. Visualizations were completed in Avizo, animation in Maya, and video production in Adobe Premiere. Working with these programs and others like them, I am able to view soft/hard tissue interactions in three dimensions as well as communicate my science to my colleagues and the public. 

Contact me:

Washington University School of Medicine in St. Louis

660 S. Euclid Avenue

St. Louis, Missouri 63110 USA

Office Phone: 314-273-1859

Lab Phone: 314-273-9014

Email: amorhardt@wustl.edu

Campus Box: #8108

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